Special guest Amber Pierce joins the team to discuss injury prevention by foam rolling vs stretching, maintaining stability in cross winds, developing a team race strategy and more in Episode 238 of The Ask a Cycling Coach Podcast.

I let a colleague borrow my Garmin for an indoor corporate event a few days before racing Galveston 70.3. What I didn’t know was she had set up alerts for every 1 minute… so for 56 miles I got a beep and notification EVERY MINUTE! It was memorable! ha.

The sailing effect if the X component of the lift force that is generated by the flow interacting with the bluff body (wheel). Lift is the force that is perpendicular to the angle of attack. Due to the shape of the wheel, since it is symmetrical, lift and sailing only occurs at yaw angles =/=0. Once you have an angle of attack that is non-zero, the lift is generated as the flow of the air is redirected due to vortex shedding and lift is the result. Since the lift is perpendicular to the angle of attack, the x direction force with respect to the wind (or a stationary observer) will be a small portion of the generated lift. The more angle of attack and the higher the lift, the more “sailing force” will occur (higher x component of the lift).

Part 2 is flow stability. As you go faster (or the wind goes faster) fluid attachment to the bluff body will eventually un-attach and then you will see stalling occur where the flow will not be redirected and lift ceases. The twitchy nature of the front end comes from the violent attachment and un-attachment that occurs and basically oscillates the wheel; the pressure differential is an observable result of this phenomena. I should note that its not the magnitude of the “pressure differential” that is the issue, but the constant fluctuation of attachment and un-attachment (or swings in pressure changes) that cause unpredictability and twitchiness. Fluid viscosity (temperature, air density, air makeup etc.) are all things that affect how the fluid behaves, along with the more important wind speed, wheel/bike speed (AKA speed of wind with respect to the wheel), angle of attack and bluff body shape (wheel shape). So, one deep wheel will not perform the same as another, and in different angles of attack and wind speeds you could see huge variations on stability and sailing.

Ultimately you are trying to keep the wind attached to the wheel and minimize the amount of violent un-attachment and reattachment that occurs when the wind “slips” off the wheel and stalls, and then reattaches. As you go deeper, the lift typically increases and as a result, sailing also increases. Unfortunately this also increases likelihood of stalling (flow un-attaching) and therefore instability of the rider. Some wheels are designed to be stable in a variety of conditions, and ultimately you would want to pick a wheelset that maximizes lift while also remains stable. Deeper does not always mean better, and some deeper wheels are more stable than others simply due to shapes. Shallower wheels will trade the lift generated for more predictable “twitching” and overall stability.

Hope I answered the topic as best as I could. If there are any actual expert experts out there feel free to chime in.

Kudos to Chad and Amber for clear information on muscle imbalance, ITB syndrome, and the role of the VMO muscle in proper tracking of the patella. Last fall I got to the point I thought I’d have to hang up the bikes due to knee issues. I’m fortunate to be in a health care system where I have access to Dr. Max Testa. My best day by far in recent memory was the day he told me after a short examination that my knees were not the problem, but that I did have a significant VMO muscle imbalance that could easily and quickly be resolved with proper PT routines, which it was. At the PT level, I heard a little about stretching, but far more about the role of muscle balance when one has opposing muscles applying opposing pressure to whatever is between them and the opposing pressures are not similar. Eventually something will give and it usually hurts. I have just read Jonathon’s post on his knee issues and need to add that a key element for me was a visit to a fitter who had insights I had not encountered before. His first observation was that I could likely benefit from 20mm pedal extenders. I had looked at them previously, but that much change seemed very extreme to me. I tried them during the fit session and knew immediately he had hit on the root cause of my issues. I simply needed a wider Q factor and until I got it with the pedal extenders, I was forcing all the leg load to to run down the lateral aspect of the leg, As soon as I tried the extenders, I discovered medial leg muscles I never knew existed. It took a short time to adapt conditioning to this change in how load was transferred down the leg, but there’s no going back now. (My screen name Classof42 signifies my birth year, so I need every advantage I can find.)

@Jonathan on being “cut throat” Ryan Leech talks about honouring our competitors. So if we don’t use all our resources (including strategies) when racing, we are doing our competitors a disservice. We are not allowing them the opportunity to improve against the best we have to offer.

So @Jonathan, it’s not that triathletes are all “nice” and not cutthroat like cyclists. It’s just that everyone has their own race plan and strategy. If you have an ego and try not to let anyone pass you, (aside from being a potential penalty) you’re burning up a lot of matches. And then your “run” turns into the Ironman zombie shuffle.

You will find out soon enough that triathlon isn’t always “nice” when you get punched in the head or get your ankles grabbed and yanked down in the swim .

Also, when talking about how sprint intervals might help in triathlon, “powering out of corners” came up, and “punchy climbs” too. I don’t think that’s a particularly smart strategy. Over 112 or even 56 miles, getting up to speed in 5 seconds vs. 8 seconds will cost you more in the end than it will save. Sprint intervals are still helpful workouts, even if it’s not something you actually use in a triathlon.